It is hypothesized that the mental health of the mother has profound influences on her children's cognitive growth. More specifically, symptoms associated with depression such as loss of interest and pleasure in usual activities, feelings of worthlessness and self reproach, diminished ability to concentrate, irritability, and (in mania) flights of ideas all influence the mother's functioning in ways that would be expected to interfere with her ability to transmit information and thinking skills to her child. The research subjects are mothers and children participating in the Child Rearing Study. These include 30 mothers diagnosed as normal and 58\diagnosed as clinically depressed. Segments of mother-child interactions are selected from nine hours video-taped sessions in a home-like environment. These interactions are coded so as to describe (a)\the extent to which mothers impart important cognitive contents to their children and (b) the methods that mothers use in order to impart cognitive contents to their children. Cognitive contents include facts about physical, social and emotional events, methods for knowledge acquisition, representation and use, and thinking and problem-solving skills. From the description of the differences between the normal and depressed mothers' teaching behaviors and from assessments of the child's responses, it will be possible to begin isolating those aspects of the mother's behavior which place the child at risk for impaired cognitive functioning. It will also be possible to determine aspects of the mother's behavior which are associated with the development of depression in the child.